Electromechanical brake interlock

Abstract

An electromechanical brake system is disclosed herein. The electromechanical brake system includes an electromechanical brake actuator, an electronic brake actuator controller coupled to the electromechanical brake actuator, and an interlock. The electromechanical brake actuator includes an actuator motor configured to turn and apply a commanded clamping force and an electromechanical brake actuator park brake configured to, responsive to being activated, maintain the commanded clamping force responsive to power to the actuator motor being turned off. The interlock is configured to receive a first signal from a park brake switch and a second signal from the electronic brake actuator controller and is further configured to activate the electromechanical brake actuator park brake in response to the first signal from the park brake switch being activated and the second signal from the electronic brake actuator controller being activated.

What is claimed is: 
     
         1 . An electromechanical brake system, the electromechanical brake system comprising:
 an electromechanical brake actuator, the electromechanical brake actuator comprising:
 an actuator motor configured to turn and apply a commanded clamping force; and 
 an electromechanical brake actuator park brake configured to, responsive to being activated, maintain the commanded clamping force responsive to power to the actuator motor being turned off; 
   an electronic brake actuator controller, the electronic brake actuator controller coupled to the electromechanical brake actuator; and   an interlock, the interlock configured to receive a first signal from a park brake switch and a second signal from the electronic brake actuator controller, the interlock further configured to activate the electromechanical brake actuator park brake in response to the first signal from the park brake switch being activated and the second signal from the electronic brake actuator controller being activated.   
     
     
         2 . The electromechanical brake system of  claim 1 , wherein the second signal is from software in the electronic brake actuator controller. 
     
     
         3 . The electromechanical brake system of  claim 1 , wherein the park brake switch is located in a cockpit of an aircraft. 
     
     
         4 . The electromechanical brake system of  claim 1 , further comprising:
 a wheel speed sensor associated with the electromechanical brake actuator, wherein the interlock is further configured to receive a wheel speed signal from the wheel speed sensor and wherein the interlock further configured to allow the electromechanical brake actuator park brake to be applied in response to the first signal from the park brake switch being activated, the second signal from software in the electronic brake actuator controller being activated, and the wheel speed signal indicated that a wheel speed is below a wheel speed threshold.   
     
     
         5 . The electromechanical brake system of  claim 4 , wherein the interlock includes an AND gate and an electrical switching element. 
     
     
         6 . The electromechanical brake system of  claim 5 , wherein the AND gate outputs a logical 1 in response to the first signal from the park brake switch being activated, the second signal from software in the electronic brake actuator controller being activated, and the wheel speed signal indicated that the wheel speed is below the wheel speed threshold thereby activating the electrical switching element and allowing the electromechanical brake actuator park brake to be applied via providing a ground via the electrical switching element that allows a differential voltage to be applied to the electromechanical brake actuator park brake. 
     
     
         7 . The electromechanical brake system of  claim 6 , wherein the differential voltage is at least one of +28 volts direct current (VDC) or +130 VDC. 
     
     
         8 . The electromechanical brake system of  claim 5 , wherein the electrical switching element is at least one of a relay or a transistor. 
     
     
         9 . The electromechanical brake system of  claim 8 , wherein the transistor is a set of transistors. 
     
     
         10 . An aircraft, the aircraft comprising:
 an electromechanical brake system, the electromechanical brake system comprising:
 an electromechanical brake actuator, the electromechanical brake actuator comprising:
 an actuator motor configured to turn and apply a commanded clamping force; and 
 an electromechanical brake actuator park brake configured to, responsive to being activated, maintain the commanded clamping force responsive to power to the actuator motor being turned off; 
 
 an electronic brake actuator controller, the electronic brake actuator controller coupled to the electromechanical brake actuator; and 
 an interlock, the interlock configured to receive a first signal from a park brake switch and a second signal from the electronic brake actuator controller, the interlock further configured to activate the electromechanical brake actuator park brake in response to the first signal from the park brake switch being activated and the second signal from the electronic brake actuator controller being activated. 
   
     
     
         11 . The aircraft of  claim 10 , wherein the second signal is from software in the electronic brake actuator controller. 
     
     
         12 . The aircraft of  claim 10 , wherein the park brake switch is located in a cockpit of the aircraft. 
     
     
         13 . The aircraft of  claim 10 , further comprising:
 a wheel speed sensor associated with the electromechanical brake actuator, wherein the interlock is further configured to receive a wheel speed signal from the wheel speed sensor and wherein the interlock further configured to allow the electromechanical brake actuator park brake to be applied in response to the first signal from the park brake switch being activated, the second signal from software in the electronic brake actuator controller being activated, and the wheel speed signal indicated that a wheel speed is below a wheel speed threshold.   
     
     
         14 . The aircraft of  claim 13 , wherein the interlock includes an AND gate and an electrical switching element. 
     
     
         15 . The aircraft of  claim 14 , wherein the AND gate outputs a logical 1 in response to the first signal from the park brake switch being activated, the second signal from software in the electronic brake actuator controller being activated, and the wheel speed signal indicated that the wheel speed is below the wheel speed threshold thereby activating the electrical switching element and allowing the electromechanical brake actuator park brake to be applied via providing a ground via the electrical switching element that allows a differential voltage to be applied to the electromechanical brake actuator park brake. 
     
     
         16 . The aircraft of  claim 15 , wherein the differential voltage is at least one of +28 volts direct current (VDC) or +130 VDC. 
     
     
         17 . The aircraft of  claim 14 , wherein the electrical switching element is at least one of a relay or a transistor. 
     
     
         18 . The aircraft of  claim 17 , wherein the transistor is a set of transistors. 
     
     
         19 . A method of parking an electromechanical brake actuator of a brake assembly comprising:
 receiving a first signal from a park brake switch;   receiving a second signal from software in an electronic brake actuator controller; and   responsive to the first signal being activated and responsive to the second signal being activated, activating, via an interlock, an electromechanical brake actuator park brake in order to park the electromechanical brake actuator and maintain a commanded clamping force responsive to power to the actuator motor being turned off.   
     
     
         20 . The method of  claim 19 , further comprising:
 receiving a wheel speed signal from a wheel speed sensor associated with the electromechanical brake actuator; and   responsive to the first signal being activated, responsive to the second signal being activated, and responsive to the wheel speed signal indicated that a wheel speed is below a wheel speed threshold, activating, via the interlock, the electromechanical brake actuator park brake in order to park the electromechanical brake actuator maintain the commanded clamping force in the event of losing power.